Breech mechanism.



A. W. SGHWARZLOSE.

Patented Oct. 28, 1 913.

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BBEEGH MEGHAHISM. APPLICATION FILED BIA-1L8, 1913.

BIA PLANOOIAPN ml, IAININOTON. D. C.

A. w. SOHWARZLOSE.

BREEGH MECHANISM.

APPLICATION FILED MAR. 8,1913.

1 ,O7'7,1 66, Patented Oct. 28, 1913.

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UTE STATES AENT FFTQEE.

ANDREAS WILHELM SOHWARZLOSE, 0F CHARLOTTENBURG, GERMANY.

BREECI-I MECHANISM.

To all whom it may concern.

Be it known that I, ANDREAS VVILHELM Sorrwanznosn, a subject of the German Eniperor, and resident of Oharlottenburg, Germany, have invented certain new and useful Improvements in Breech Mechanism, of which the following is a specification.

The object of the invent-ion is to provide a breech mechanism of this kind in which the front member of the knuckle is extended up to the rear end of the barrel so that at the moment of firing the back thrust of the cartridge head is not received as heretofore by the breech block but directly by the front member of the knuckle joint and is transmitted to the rear member. In the place of three points of articulation as heretofore, only two have in this arrangement to bear the strain of the gas pressure and thus the sagging of the breech mechanism after a prolonged use is considerably lessened. The front surface of the front member of the knuckle applying itself against the head of the cartridge is arranged in such a manner with reference to its center of rotation in the head of the breech mechanism that at the moment of firing the gas pressure causes the breech knuckle to swing to its open position, and thus automatically open the breech mechanism even when the bending point of the knuckle joint is positioned, before the firing, considerably below the dead center. The cartridge case, after having moved backward a very short distance, is received and held by abutments of the head of the breech mechanism in order to prevent the head of the cartridge case from being torn off.

The accompanying drawings show several forms of embodiments of this invention and in these drawings: Figure 1 shows a longitudinal section, partly in side elevation of the knuckle breech mechanism of a gun in its closed position. Fig. 2 shows several views of the head of the mechanism. Fig. 3 also shows several views of the front member of the knuckle joint. Figs. 4 and 5 show longitudinal sectional views, with the parts of the breech mechanism in side elevation, of a modified form of the knuckle joint breech mechanism of a gun in the closed and open positions respectively. Fig. 6 is a cross section of same on line 1-2 of Fig. 4-. Figs. 7 and 7 show respectively side and front elevation of one of the guide plates. Figs. 8 and 8 show similar views Specification of Letters Patent.

Application filed March 8, 1913.

Patented Oct. 28, 1913. Serial No. 753,045.

of the extractor. Figs. 9 and 9 show two detail views of the hinge pin of the knuckle. Figs. 10 and 11 show longitudinal sectional v ews with the parts of the breech mechanism in side elevation, of a third form of the breech mechanism applied to machine guns, in the closed and open position respectively. Fig. 12 is a cross sectional view of the mechanism on line 34 of Fig. 10.

The barrel 1 is rigidly secured by means of screw threads with the breech casing h and both parts are rigidly connected in the well known manner with the stock of the gun. The breech mechanism comprises the block 1) and the knuckle joint members s and g which are connected in the usual way with each other at the bending point by means of the bolt Z2 while at the rear end they oscillate in the breech casing around the bolt cl. The guide head is composed of a substantially semi-cylindrical part 7) the front end of which is cut off straight and is provided at this place with the depression for the cartridge head, as well as with the two lateral members or wings e which are guided in a straight line in longitudinal grooves of the breech casing. The wings are provided on their inside with are shaped ribs 01 which when the breech mechanism is put together engage the two similarly shaped milled out portions 8 of the front member s of the knuckle and thus couple the knuckle in a rotary manner with the breech head or block. The front part of the knuckle is provided to this end with an arcuate milled out portion 8 by means of which it is permitted to rotate over the semi-cylindrical surface of the head 0). The axis of rotation 0 (Fig. 1) between the knuckle and the breech head or block is here positioned at the height of the head of the cartridge in the barrel. The breech head or block is provided with a passage '0 centrally arranged with reference to the axis of the barrel and through which the cylindrical projection s of the front member of the knuckle passes. lVhen the breech mechanism is closed (Fig. 1) the front end of the projection fits against the head of the car tridge in the barrel. The projection thus receives, when the shot is fired, the back pressure of the head of the cartridge and transmits it directly 2'. 6. without passing through a breech block or head, to the breech knuckle joint. Now, as the center of r0tation a of the articulation is situated above the projection s i. e. ecc'entrically withreference to its front end applied against the cartridge head,' the"lmuckle,' when-the shot" received by the abutmentsi'o of the breech head or bl ock whichwhen the breechmechanism is closed stand a :short distance behind the, frontl end ofthe knuckle joint.

In the second form -of embodiment-shown by Figs. 4: to=9, in order tocause, when the knuckle joint is automatically swung, open by the'back pressure of 'thecartridge, the

knuckle joint tosupport the cartridge case longer than-in the first form of embodiment the stroke'performed' by the hingeof the knuckle joint being the same, two or 'more superposed fulcrums have been-:provided on the rear member of the knuckle join which fulcrums are adaptedto apply-themselves one after the other against the breech casing during the-opening of the mecha nism." The cylindrically shaped bearing surfaces are arranged, accordingto'this invention,.not one above the other but side by side in such a manner that the knuckle of the. breech mechanism bears continuously against a comparatively large surface of the breech casing, Consequently the bearing surfaces cannot, when continuous firing is carried on, be forced back as would be the case if only one continuous curvesha-ped bearing surface has been provided on the knuckle and on the breech casing,- because in the latter case'only a sma-ll part of the whole bearing surfaces would be in close contact during the opening of the mechanism.

In the new breech mechanismithe knuckle joint, naturally must be mounted with a little more clearance than heretofore on the rear hinge bolt (Z so'that the rea member of the knuckle joint can, with its upper fulcrum, swing slightly forward during the closing of the'mechanism as soon as the lower fulcrum bears against the breech cas ing. In order to avoid, when the breech mechanism is automatically opened, the case of the-cartridge fired being loosened late,- the front member of the knuckle joint strikes, during the first part of the swingingup motion,with a shoulder against a fixed abutment of the breech casing, the said shoulder being positioned above the frontfulcrumof said front-part. The member of the knuckle thus acts like a knee lever against the member carrying the eX- tractor and loosens any cartridge case which might be wedged in the cartridge chamber of the barrel;

, The sagging of the breech mechanism which takes place after a prolonged use is prevented according to the present invention by the hinge bolt being eccentrically con-' structed at its centerr This rotation of the bolts allows of its higher positioned side being brought forward and of the knuckle joint being, lengthened ina corresponding manner. Instead" of the breech head or block, with its solid'front part and its two guidewi-ngs, two separate guide plates areusedto insure the longitudinal guiding of the knuckle joint-,these plates being held on the knuckle joint by the extractor when the breechmechanism is removed vfrom the breech casing. The front member of the knuckle can in this embodiment beconinued up to the'barrel without being reduced-in thickness whereby the breech mechanism becomes considerably more stable than in the construction-first described. The breech casing h. is inthis form, too, rigidly secured by means of screw threads to the barrel; the members 5 and g of the knuckle are con-nectedat the bendingpointby means of the bolt 7) and 'with the'breech casing by means of the wing shaft cl, In this instance the member 5/" is provided however at its rear end with an'additional central bearing 9 The rear part ofthe latter forms a cylindrical: surface 9 theaxis of which is at I. When the breech mechanism is closed this surface bears against the milled out portion 72 having the same radius of curvature as the/breech casing (Figs. 4t and 5) while the two lateral trunnions of the member, the axis ofwhich trunnions is at II, are at the samemoment at adistance of about 0.3 mm. from their rear bearing surfaces h in the breech casing. Now, at the moment of firing the member s of the joint, the front axis of rotation being at 0, is thrown upward by the back pressure of the cartridge head in the manner described for the first form of embodiment, the rear member 9 first rotates around the axis I until the bending point 1 of the knuckle joint has been swung intothe position 2. Duringthis movement the two bearings g and g of the rear'member have moved backward to such an extent that their rear parts of the front surface s of the front member recede slightly during the opening motion until the point 2 is reached. Then the point 2 is passed, the rear member of the knuckle, during the continuation of its swinging motion pushes the upper side of the front surface .9 forward and thus limits the distance it would move backward owing to the angular motion because the dead center of the axis IT is only at 3. It is only when this point has been passed, that the front surface s withdraws its top from the head of the cartridge. But then the projectile has already left the barrel.

In Fig. at the action of the two axes I and H with the bending point of the knuckle up to the second dead center 3 has been shown by means of dot and dash lines. The front surface 8 of the front member s is slightly inclined at s in order to prevent this surface sticking fast to the cartridge head through wedging when the bending point of the knuckle joint swings from 2 to 3. When the breech is closed the line of pressure from c to 1 passes slightly below the bending point 1 and, as the cartridge is fired, the entire knuckle joint moves backward till 9 contacts with 71. whereupon the point 1 moves upward to the position 2. At this time 9 and k begin to separate and the rear member 9 to revolve about H as a center. The line of pressure now extends from 0 to II and lies above 1 but the inertia of movement of the joint upward carries the point 1 through this new line of pressure and the breech opens, the two members straightening during the first part of the movement and thus holding the cartridge in place momentarily. Shortly before the knuckle joint has passed, during the opening motion, the second de ti center, the shoulder s of the front member of the knuckle joint engages the abutment 7L (Figs. 4. and 5) of the breech casing. The knuckle joint, when continuing its swinging motion, then retates at the front momentarily around the shoulder s acting like a knee lever against the guide plate ".0 and the extractor a hooked therein, so that the cartridge case is energetically loosened in the barrel. The two guide plates w sliding in the longitudinal grooves k of the breech casing are provided on their inner sides with arcuate grooves e0 (Fig. 7) with which, when the breech mechanism is put together, the front member of the knuckle joint engages by means of the two similarly shaped lateral ribs 2. whereby it is connected in a rotatable manner with the plates. The latter carry below projecting ribs Q02 which when the iechanism is closed, extend slightly beyond the front member (Figs. 4, and serve to keep the uppermost cartridge of the maga- Zine away from the knuckle joint. Each plate is provided at the front with a bearing 10 (Fig. 7) which serves to secure the extractor a. The latter, before the parts are inserted into the breech casing, is first slid with its two lateral ears a (Figs. 5, 8) from the front on the guide plates which are already connected with the member s of the knuckle. Thereafter its holding studs are tilted down into the corresponding bearings of the plates and are thus connected with the latter (Fig. 5). The extractor spring f (Figs. 4, 6) which is then secured in an elongated hole of the front member of the knuckle joint, always forces the extractor yieldingly downward and at the same time prevents it from sliding from the guide plates. The latter then are still adapted to rotate on the knuckle but they are prevented from falling off. Owing to the breech head or block being replaced by the two guide plates, it is possible to place the front member of the knuckle joint also much lower than heretofore so that the devices for firing are now positioned in axial alinement to the axis of the bore of the barrel and the firing pin need no longer be made eccentric as this was necessary in the construction described first.

Fig. 9 shows a hinge boltthe central part b of which is eccentrically arranged with reference to the lateral part if. By rotating this belt 180 the flexing point of the knuckle joint can be lowered to such an extent that at the moment of firing the breech mechanism is no longer opened automatically. in machine guns the eccentric bolt can be used to take up the clearance which after prolonged shooting is formed between the breech mechanism and the cartridge head owing to the sagging of the knuckle joint.

The Figs. 10 and 11 show a third form of embodiment of the new breech mechanism with knuckle oint applied to a machine gun. This form of embodiment is distinguished in that at the moment of firing the breech mechanism under the back pressure of the cartridge head, first recedes a little as in the forms of embodiment already described in order to impart to the knuckle the momentum necessary for the automatic opening but then supports the fired cartridge case immovably with reference to the breech casing until the projectile has left the barrel. In order to attain the result cited above the front member of the knuckle joint swings here during the opening at the front end successively around two axes of rotation one of which as in the forms of embodiment described in the first instance, lies at the height of the head of the cartridge case while the second one is positioned behind the cartridge head. Besides, in this con struction the ejection of the cartridge cases is also effected by the front member of the knuckle so that the ejector is dispensed with. Besides, the guide plates for the front member ofthe-:knucldewvill serve atthe same:

time as:'extractors, one'of them being pro-' vlded' to thls effect at its front: end wlth an inwardly pro ect1ng claw which engages the groove of the cartridge engaged in the ban" rel-and thus, when'the breech mechanism is opened also pulls this cartridge. casingba'ck ward In order to prevent, in machine guns pro ;;vided with a cooling jacket, the heating of the breech-casing .as well as the lengthening.

thus produced in the latter and which has a disturbing influence upon the breech mechanism, the'rear tightening l'lIlgz'fllt is arrangedin such a manned between the bar'- rel and -the acket that the cooling: liquid 1s allowedto circulate up to the rear opening of the bar-rel. In the mechanism shown by' Figs. 10 and 11, the breech casing'h and the rearmember- 9 of the knuckle are' con structed like'these parts in the second form' ofembodiment described above. However,

the-hinged connection between the member' and the guide plates 10 is effected here-by rmeans:otcylindricalpivots w which en-" gagecorrespondingbored out holes on both The vertical disides of the member s. tance'of the front axis of rctatlon 0 thus formed from the axis of the barrel is smaller than the-diameter of the cartridge head;

Besides the front surfaces is curved at s in suclra manner that, whenthe opening takes place automatically the mechanism cooperating with the axes'l and-H of the 'rear member' oftheknuckle shores up the firedcartrldge case 1n the barrel as long as the gas pressure-lasts. Inthis construction in order to cause the back pressure 'of the cartridge head to impart to the' knuckle joint ance is produced at the top between theplates and the breechcasing. Thus it is that at the moment of firing the knuckle joint acted upon by the back pressure of the cartridge head swings upward first around the fulcrum 0 (FigPlO) in the manner described for the first form of 'embodiment' and then after a short movement continues its rotatory movement round the fulcrunrc The front member of the" knuckle-when swinging upward strikes herewiththe stud 8 against the head of the extracted car tridge case and fiings the latter downward or sidewise (Fig. 11).

plates w, whichwhen the breech mechanism is closed, suddenly snap, like the well known extractors, :in front ofthe base of' the :car-

The extraction of the fired cartridge case is producedby'inwardlyv projecting: claws I a of the guide" tri c ge'= engagednn thebarrel, the guide" grooves:-/z, being to this end" enlarged a little at their front-part: The spring f connects 'botlrplates and pulls them constantly toward the breech knuckle: 1

Thebarrell is connectedwit-h'the breech 7 casing in' the wel l known-'manner by "means i of the interrupted screw Z forming a-kind l of 'bayonet j ointz The tighteningwasher 1* which: maintains watertightness betweenboth parts and the breech mechanism, is

positioned a :short distance in frontof the breech mecli-anisnr so that the 'cooling liquid= is allowed toarr iveat the rearopening of of a knuckle 'oint comprisin front and rear members which are in alinement when 'the breech isclosed, the frontmember extending up to the rear end of the: barrel whereby at the moment of :firing Said fr Ont member 'di rectly *receives the ba'cklpressure of the head of the cartridgeinsaidbarrehand transmits saidpressure directly to saidrear member of the knuckle whereby the knuckle joint is vbroken' and the members"disalined, substantially as' andfor the purpose set forth 2. In i a breech -m'echanism' the combinatio-niwithtlie barrel and the breech-casing, of a knuckle joint: comprising a front member and a rear member; means :for c0nnectingrthe rear end=of 'said 'rear member with the-said breec'hcasing in sucha manner'as to provide 'a plurality of superposed axes of rotation adaptedg-when the mechanismis automaticallyopen, to -successively act as pivot point's for saidrear member, the mem-' ber and casing having a plurality of juxtaposed bearing surfacesconcentric with said axes, substantially as described.

3. In a breech mechanism the-combination with the barreland the breech casing, of a knuckle joint comprising a front member anda rear memberfa shoulder provided on-the said front member above its axis of k rotation,.anrabutment provided on the said breech casing"and adapted when the-said' front member swings" open,-'to be engaged by the said 'sh'oulder'andmeans on said shoulder arranged to engage and'loosena fired cartridgecase during opening move pivotally connected to'the front end of said-130- provided on the said guide plates and adapted to engage the groove of the cartridge engaged in said barrel and to thus act as an extractor for same, substantially as 15 set forth.

In testimony whereof I have hereunto set my hand in presence of two witnesses.

ANDREAS WILHELM SCHWARZLOSE. lVit-nesses HENRY HASPER, WVOLDEMAR HAUPT.

front member and an extractor carried by the said guide plates and the said front member, substantially as and for the purpose set forth.

5. In a breech mechanism the combination With the barrel and the breech casing, of a knuckle joint comprising a front mem ber and a rear member, guide plates pivotally connected to the front end of said front member and slidably mounted in the said breech casing, inwardly projecting claws Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

